Long-chain omega-3 polyunsaturated fatty acids (PUFAs), which are present in cold-water fish such as herring or salmon and are commercially available in capsules (over the counter and by prescription), can decrease fasting triglyceride concentrations 20-50% by reducing hepatic triglyceride production and increasing triglyceride clearance.1 With long-term intake, they may increase HDL-C.
Fish Oil Supplements. JAMA. 2014;312(8):839–840. doi:10.1001/jama.2014.9758